[Aim]  To investigate the impact of ingesting microplastics on the growth, development, and predatory capabilities of Arma chinensis. In addition, this paper aims to provide valuable insights on microplastic migration and transformation within the terrestrial insect food chain. [Methods]  Polyethylene microplastics (PE-MPs) were incorporated into the diet of Tenebrio molitor larvae, which were subsequently fed to A. chinensis. The survival rate and body weight of   T. molitor larvae, the growth and development of A. chinensis, and the predatory ability of A. chinensis, were assessed. [Results]  Consumption of PE-MPs caused a significant decrease in both the survival and body weight of T. molitor larvae (P < 0.05). Consuming T. molitor larvae that had consumed PE-MPs also shortened the developmental duration of A. chinensis nymphs, increased the body weight of A. chinensis adults, and increased the mortality rates of both nymphs and adults. It also reduced the predatory ability of A. chinensis adults (P < 0.05). Polyethylene microplastics were detected in the intestinal tracts of both T. molitor larvae and A. chinensis, indicating that these were probably transferred to the latter through the food chain. [Conclusion]  The incorporation of PE-MPs in the diet of T. molitor larvae not only had a detrimental impact on their survival, but also resulted in the transmission of PE-MPs to A. chinensis, which also reduced the survival and predatory capability of this species.